/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.druid.server.compaction;

import java.util.Iterator;
import java.util.List;

/**
 * Iterator over compactible segments.
 */
public interface CompactionSegmentIterator extends Iterator<CompactionCandidate>
{
  /**
   * List of candidate segments that are already compacted and do not need to be
   * compacted again. None of these segments are returned by {@link #next()}.
   */
  List<CompactionCandidate> getCompactedSegments();

  /**
   * List of candidate segments that have been skipped for compaction as they
   * cannot be compacted due to some reason. None of these segments are returned
   * by {@link #next()}.
   */
  List<CompactionCandidate> getSkippedSegments();

}
